Turn on pc, but no dispaly just black screen

Hi,
i have recently been having a problem with my computer. I was having problems with updating a program which is for my logitech mouse which was something related to my registry. After the reboot from the install i was i waS using the computer for a few minutes then i get a blue screen and a mesage saying " PAGE_FAULT_IN_NONPAGED_AREA". I just turned it off then booted up again but to find that my pc turns on ok (eg all the components turn on) but i do not get a display come up on my moniter, just a black screen. usually at startup there would be a single beep from the mobo but now there isnt. aswell as this problem i also had issue with the pc restarting itself randomly.

i dont think this is a problem relating to my moniter as it is quite new and i have been using it with no problems


I have been reading around and havent come to a definate answer.

I have seen people saying stuff like "taking the mobo battery out for a period of time to reset the bios"

do i need to clean the registry with a program? how do i do that coz i cant see the screen?:S
i have a few registry programs but usually use uniblue registry booster, it found a few errors before my last reboot but i chose to leave them and do them later. could it be these errors that cause the prob?


all info and possible solutions are much appreciated,